Ken Bates, who has been confirmed as Leeds United's new owner, at Elland Road back in 2005. Photograph: Reuters

Following years of pressure from politicians and the media, the Leeds United chairman, Ken Bates, hassaid he had taken control of the club in order to quell speculation over its secretive ownership structure.

The former Chelsea owner, who banned the Guardian from Elland Road as a result of persistent questioning over the identity of the club's offshore owners, said he had been moved to take control of its holding company to "bring an end to speculation". But that raises fresh questions over who owned FSF Limited, the firm that held 73% of the club's holding company, before Bates bought it for an undisclosed sum, and his motivations for doing so now.

The move follows pressure from the ongoing parliamentary inquiry into football governance and the Premier League's insistence it would interpret its rules in a "more stern" manner than the Football League if Leeds were promoted.

"The scaremongering arising out of the football governance enquiry has not been helpful and, whilst the board were always confident that there were no issues, recognise the concern the unknown outcome of any Premier League questions, may have on our members," said Leeds in a statement.

"To address this issue, and in the hope that this brings an end to the speculation, the chairman, Ken Bates, has completed the purchase of FSF Limited for an undisclosed sum. FSF Limited is now owned by Outro Limited, which is wholly owned by Ken Bates."

It added: "This change in ownership structure makes Ken Bates the controlling shareholder of Leeds United and delivers the transparency sought."

The new ownership statement, also published on the Leeds website, said Bates was the sole owner of Outro, which is registered in Nevis in the West Indies.

Both the Football League and the Premier League demand that clubs reveal any individual with a shareholding of more than 10%. The rules were brought in following pressure from fans and the media and amid concern over the offshore ownership structure of clubs, including Leeds and Notts County.

Leeds United have always maintained that since no individual owned more than 10% of the offshore trust that in turn owned FSF Limited there was no need to make their names public.

The Leeds chief executive, Shaun Harvey, told the committee in March that FSF was previously owned by "three discretionary trusts that are all managed by trustees out of Switzerland" and that he didn't know the identity of individual shareholders.

He added: "The trustees have appointed two members to run the trust's interest in Leeds United Football Club; Mr Patrick Murrin and Mr Peter Boatman, who asks Mr Ken Bates to chair the board."

In an earlier court case, Bates had said he and Murrin were the owners of the club as holders of the two management shares in FSF. But he later said he had made an "error" and that there were in fact 10,000 shares in FSF with undisclosed owners.

The Football League has consistently said the structure complies with its rules but has never said whether it had seen proof of the identity of the owners.

It is believed that Bates recently met the Premier League chief executive, Richard Scudamore, and was told the club would be expected to provide more transparency if Leeds were promoted.

"The Football League have one view of how to interpret that rule and we have a more stern, or harsh, view of what the rule means," Scudamore told the culture, media and sport select committee last month. Leeds are seventh in the Championship and look likely to miss out on the play offs, so Scudamore's resolve would not have been tested imminently.

Bates originally bought Leeds in 2005 from the consortium of local businessmen who had attempted to rescue the club following the financial implosion of the Peter Ridsdale era. It entered administration in May 2007 and was controversially bought by FSF in July that year in the midst of a legal challenge by Her Majesty's Revenue and Customs (later dropped) and a host of unanswered questions about the sale process and ownership structure.